Ribbon type gas burner with flame control



Sept. 24', 1957 o. WILDERMANN 7,

RIBBON TYPE GAS BURNER WITH FLAME CONTROL Filed June 28, 1954 5Sheets-Sheet 1 INVENTOR Otto wildermonn warm ATTOR EY Sept. 24, 1957 o.WILDERMANN 2,807,320 RIBBON TYPE GAS BURNER WITH FLAME CONTROL FiledJune 28, 1954 5 Sheets-Sheet 2 Fig. 5.

Fig. 6.

INVENTOR Otto Wildermunn w 1 w 104w? 4! ATTOR Y I Filed June 28, 1954 P4, 1957 o. WILDERMANN 2,807,320

RIBBON TYPE GAS BURNER WITH FLAME CONTROL 5 Sheets-Sheet 3 INVENTOR OttovWildermunn I2 23 Q BYJ/m m I ATTO EY P 1957 o. WILDERMANN 2,807,20

RIBBON TYPE GAS BURNER WITH FLAME CONTROL Filed June 28, 1954 I 5Sheets-Sheet 4 II I I I II I: pl K II! I I 5 5555 m If m II I m m I II TI I I O .Q a; i 03' .9 I I I .5? LI. I LL I I I I I I n I i; I' I 2:3

& il I I II II I l k I Q I -3; 55

I INVENTOR I Oflo Wildermunn 1% 3 w H m/ru YA TTORN P 24, 1957 o.WILDERMANN I 2,807,320

RIBBON TYPE GAS BURNER WITH FLAME CONTROL.

Filed June 28, 1954 5 Sheets-Sheet 5 'IIIIIIIIIIIIIIA'IIIII Fig. l2

INVENTOR Otto Wilderynann ATT IDRNEY llnited States Patent Qfl rce1%?32] Fatented Sept 24, 1957 RIBBGN TYPE GAS BURNER WITH FLAME CDNTRQL11 Claims. (Cl. 158-414) This invention relates to improvements inribbon type gas burners so called because they produce a ribbon likeflame along the burner mouth extending along the length of thehorizontal burner tube that constitutes the burner housing.

More particularly this invention is directed to such ribbon type gasburners in which there are provided means for controlling or adjustingthe flame intensity variously along the length of the burner mouth.indeed burners of such type are known which have a gas distributor tubedisposed interiorly of and concentric with the tubular burner housing,so that gas entering the distributor tube will pass through ports or gaspassages suitably disposed along the distributor tube, whereby the gaswill transfer and spread into and along the surrounding gas chamberspace for combustion along the longitudinal burner mouth in a ribbontype flame. In conjunction with such a gas distributor tube there arefound means or devices for controlling the height or intensity of theflame along the burner in a complementary fashion, that it is in amannerwhereby the flame is rendered greatest at the gas inlet end to drop offtoward the dead end of the burner, or conversely the flame is renderedgreatest at'the dead end to taper off towards the inlet end. Hence, itis a limitation of this manner of control that one end of the flame isincreased at the expense of the opposite end of the flange. In otherwords, the known'flame controls of this character are, limited becauseof this interdependence of the heating effects in the sense that anincrease of flame intensity at the near end of the burner will produce adecrease at the far end, and vice versa an increase at the far end willinterdependently produce a decrease at the near end of the burner tube.Therefore, these known flame controls do not meet a problem that ariseswhere the requirements for heat distribution along the length of theflame are such as to call for a burner that provides greater operationaladaptability and versatility as well as more positively controllableflame distribution. The problem which thus presents itself is to provideburner control means whereby the adjustment of one portion or zone ofthe flame is substantially independent of other zones. A more specificproblem is to have an intermediate portion of the flame independentlyadjustable relative to the end portions thereof.

in order to attain this object of zonewise independent flame control,this invention provides within the burner housing one or more annularpartitions or partitioning ribs which by their spacing from one anotheralong the gas distributor tube define the sequence of the zones or ofannular gas supply chambers within the burner housing, which supplychambers communicate with the longitudinal burner mouth. Each annulargas chamber receives gas at an adjusted rate through acorrespondingindividually adjusted gas passage area, while gas leakage from onechamber to the next may be minimized by the partitions or ribs. The gasdistributor tube is axially removable from the burner housing for thepurpose of gonewis e flarne adjustment. That to say, there is providedfor each chamber a blank-off member associated with the distributortube, which blank-01f members have gas ports or gas passage openingsregisterable with similar ones in the distributor tube. By adjustingthese individual blank-off members relative to. the distributor tube,the effective gas passage area of each chamber and thus the height andintensity of the flame for any one zonemay be varied individually andsubstantially independently of the other Zones.

According to one feature, the blank-ofl? members are disposed internallyof the distributor tube and are individually settable through openingsin the wall of the distributor tube. Furthermore, the annularpartitioning ribs are unitary with the burner housing, so that the gasdistributor tube with its internal blank-off members may extend throughand be slidably fitted into the openings or bores of these ribs. If theassembly of distributor tube and interior blank-elf members he removedfrom the housing, adjustment of the respective gas passage areas can bemade by manipulating the interior blankoff members from without thedistributor tube.

According to a more specific feature, the blank-off members are in theform of short lengths of blank-01f tubes of a diameter substantiallycorresponding to the interior contour of the gas distributor tube.Adjusting and position fixing means for the blank-off members comriselocking members extending outwardly from the tank-off means. Eachlocking member extends into a respective cutout area provided in thedistributor tube. Each such locking member is operable to fixinglyengage the edge portion defining the cutout area, for securing anadjusted position of the blank-off means. The locking members thusengaged are substantially flush relative to the circumference of thetube to provide for clearing the cores of the partitioning ribs duringthe longitudinal movement therethrough of the tube when the same iswithdrawn or inserted relative to the burner housing. More specifically,the adjusting and position fixing means for the blank-oif tubes comprisefixing screws threaded into the blank-off tubes through elongatedopenings or cutouts provided in the gas distributor tube, whereby theblank-elf tubes may be fixed in their adjusted position relative to thedistributor tube. More specifically, the position fixing screws haveconically countersunk flat heads fixingly engaging the edge portionswhich define associated openings or cutout areas in the distributortube, so that the distributor tube itself may present a protrusion-freeouter surface to allow for smooth passage of the tube through the boresof the partitioning ribs. That is to say, such a fixing screw has a flathead provided with a conical seating surface, and the edge portiondefining the associated opening is bevelled substantially, correspondingto the conicity of the seating surface of the head of the screw. In thisway, the conical seating surface of the screw head will fixingly engageuponthe bevel face when the screw is tightened.

According to another feature, the partitioning is such that anintermediate zone of the flame may be adjustable relative to adjoiningend zones of the flame.

According to one embodiment, the burner construction is equipped for theuse of pre-mixed gas, that is a suitable pre-mixture of gas and air.,That is, a gas inlet head hollow supply fitting for pre-rnixed gas isprovided at the inlet end of the burner housing, which fitting issubstantially coaxial with the horizontal burner axis and communicateswith the inlet end of the gas distributing tube. At its outer end thishollow gas supply fitting has a closure member or plug which isremovable without disturbance of a gas supply connection leading to thefitting, so that after removal of the plug the gas distributing tube canbe withdrawn from the btuner housing whenevle; a zonewise flameadjustment is to be made upon that to According toanother embodiment,the burner construction is equipped with a gas inlet head in the form ofan inspirator head, that is an injector type gas supply nozzlewhichjmixes gas and air injector-fashion at the burner. itself. In thisembodiment a venturi-shaped constriction member is coaxially and rigidlyconnected with the gas distributing tube so as to constitute therewith asubassembly unit removable from the burner housing for the purpose ofmaking zonewise flame adjustment. The outer end or inlet end of theconstriction member has associated therewith and surrounding it aremovable nozzle housing which comprises a gas supply nozzle or gas jethousing in coaxial relationship injector-fashion with the constrictionmember or gas distributing tube, the relationship of the parts beingsuch that the nozzle housing is removable with respect to the burnerhousing as well as relative to the constriction member, while theventurishaped member with its gas distributing tube is in turn removableper se from the burner housing.

In a more specific embodiment, there is provided a stationary mountingor shield member whiclt has a threaded opening. The tubular burnerhousing is screwed into. that opening at the inner end thereof, whereasthe constriction member with its distributing tube is screwed into theouter end of that opening. The nozzle housing surrounds and fits overthe outer end portion of the nozzle member and is removably fastenedthereto.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

In the drawings:

Figure 1 is a part-sectional side view of one embodi- 'ment of theburner construction equipped with a gas inlet head for the use ofpre-mixed gas, with zonewise flame control indicated along the length ofthe burner housing.

Figures 2, 3, 4 illustrate various possibilities wise flame control.

Figure 5 is a greatly enlarged detail vertical sectional view of anintermediate portion of the burner structure of Figure 1.

Figure 6 is a longitudinal horizontal sectional view taken on line M ofFigure 5.

Figure. 7 is. a cross-sectional view taken on line 7-7 of Figure 5.

Figure .8 is a cross-sectional view in perspective taken on line 8-8 ofFigure 5 and with a portion of the burner housing broken away.

Figure 9 is a part-sectional greatly enlarged detail view of the frontend portion of the burner structure of Figure l equipped with a gasinlet head for pre-mixed gas supply.

Figure 10 is a view of the parts of Figure 9 exploded to illustrate theremoval of the internal gas distributing tube.

Figure 10 is a side view in greatly reduced scale of the gasdistributing tube of Figure 10 fully withdrawn.

Figure 11 is an enlarged part-sectional detail view of the front endportion of the burner structure according to another embodimentproviding a gas inlet head in the form of an injector type inspiratorhead, where the venturishaped constriction member is unitary with. thegas distn'butingytube.

Figure 12 is a view of the parts of Figure 11 exploded, to illustratethe removal of the internal gas distributing tube. 1

Figure 12 is a side view in greatly reduced scale of ,thegas-distributing tube of Figure 12 fully withdrawn. According to oneembodiment of Figures 1 to 10*, the

burner unit 10 is shown equipped for the use of premixed of zonegas. Theburner unit is here shown to be mounted in and supported by an ovenfront wall W1 and a rear wall W2 (see Figure 1). This burner unitcomprises a housing structure 11 of length 11, a gas distributor tube 12within and coaxial with the housing structure, a bracket 13 forsupporting the rear end of the housing structure upon the rear wall W2,a front shield plate 14 connected with the front end of the housingstructure for supporting the same upon the front wall W1, a hollow gassupply fitting 15 at the front end of the housing structure andconnected with the shield plate 14 at the front thereof to havecommunication with the internal distributor tube 12. The shield plate 14in turn is carried by and removably fastened to a flanged liner sleeve16 mounted in the front wall W1 and defining an opening 0 in the wall,through which the burner unit as a whole may be inserted or withdrawn.

The housing structure 11 comprises a cast iron burner housing member 17proper substantially tubular and of the length In providing alongitudinal burner mouth M of the length la; a tubular rearwardextension nipple 18 for closing the rear end of the housing 17 andsupporting the same through bracket 13 upon the rear wall We; and atubular forward extension nipple 19 supporting the front end of thehousing through shield plate 14 upon the front wall W1. That is to say,the rearward closing nipple 18 is screwed into the rear end of the castiron housing 17 and thus rigidly and coaxially connected therewith. Theforward nipple 19 is screwed into the front end of the cast iron housing17 and thus rigidly and coaxially connected therewith, the front end ofthis nipple in turn being screwed into the shield plate 14 and thusrigidly connected therewith. The hollow gas supply fitting 15 is screwedinto the shield plate 14 at the outer face thereof, thus connecting withthe burner housing to supply gas to and into the distributor tube 12,the fitting 15 having a lateral gas supply connection 19 with controlvalve 19 At its outer end the fitting 15 has a removable closure memberin the form of a screw plug 20, so that with the plug removed thedistributor tube 12 can be withdrawn from the housing withoutdisturbance of the gas supply connection 19.

The cast iron housing 17 is formed interiorly with a pair of annularribs 21 and 22 which are bored to such a diameter as to allow forsliding passage therethrough of. the distributor tube 12. In this waythere are provided within the housing 17 a series of three annular gassupply chambers 23, 24, 25 of the lengths a, b, c, respectively,defining the lengths of corresponding zones of the ribbon type flamealong the burner mouth M.

For each of the supply chambers 23, 24, 25 the distributor tube 12 isprovided with a longitudinally elongated gas passage opening 26, and foreach such opening there is provided within the distributor tube ablank-off tube T of the length [4 having a gas passage openingsubstantially registerable with the associated opening in the tube. Thusthere are three blank-off tubes T having an outside diametersubstantially conforming and slidably fitted to the interior contour ordiameter of the distributor tube 12. Each blank-on? tube T has a gaspassage opening 32 and is rotationally adjustable within the distributortube 12 to a degree whereby the gas passage openings in the distributortube 12 can be blanked off to any extent desired. Within and along theburner mouth M (see Figure 8) there extends a corrugated metal strip Pto indicate the use here of well known ribbon inserts of this kind.

For the purpose of effecting such blank-off adjustment and for fixing ablank-off tube T in its respective adjusted blanlcolf position there areprovided in the distributor tube 12 a pair of transverse auxiliaryelongated openings 33 and 34 for each blank-off tube. That is to say,upon Withdrawal of the distributor tube 12 from the housing structure 11the blank-off tube T within may be adjusted to a desired blank-01fposition by manipulating the screws 33 and 34*, and the thus adjusteddistributor tube restored to its position within the housing structure.

It will be noted that the position fixing screws 33' and 34 have a flathead provided with a conical seating surface, and that the auxiliaryopenings 33 and 34 have their edge portion bevelled substantially inaccordance with the conicity of the heads of the screws. In this way,when the screws are tightened, the screw heads will be substantiallyflush with the outer circumferential face of the distributor tube 12 sothat the same may be slid unobstructedly through the bores in theannular partitions or ribs 21 and 22.

The embodiment of the burner structure shown in Figures 11, 12, 12 isequipped with a gas inlet head in the form of a removable inspiratorhead 35 associated with a venturi-shaped injector member 36 which inturn is unitary with an internal gas distributor tube 37 (which tubeotherwise corresponds to the distributor tube 12 in the Figures 1 to 10*embodiment). In other words, this embodiment provides the removable gasinspirator head 35 along with a removable sub-assembly unit whichcomprises the air injector member 36. The injector member 36 is shown tohave a reduced inner end portion 36 fitted into the associated end ofthe distributor tube 37 and fixed thereto as by a countersunk screw 38.

All component parts of the housing structure 11, namely a cast ironhousing member 17' with burner mouth M, a rearward tubular closingnipple (corresponding to nipple 18 of Figure 1 but here not shown), aforward extension nipple (corresponding to nipple 19 of Figure l buthere not shown), and a shield plate 14, all are substantially the sameas the corresponding parts of the embodiment of Figures 1 to 10described above. Equally the same are the compartmentations of theinterior of the housing member 17' by means of annular partitioning ribs(corresponding to ribs 21 and 22 of Figure 1 but here not shown), andthe provision of the gas distributor tube 37 with gas passage openings26' and associated interior adjustable blank-off tubes T having gaspassage openings 32', all as described above with respect to the gasdistributor tube 12 in the embodiment of Figures 1 to 10 Within andalong the burner mouth M (see Figure 8) there extends a corrugated metalstrip P to indicate the use here of well known ribbon inserts of thiskind.

The venturi-shaped injector member of the total length I is in the formof a generally tubular member having a slender portion In extending intothe housing structure of the burner, a threaded portion n whereby thismember is screwed into the shield plate 14, a shoulder portion to setagainst the front face of the shield plate, and a relatively reducedmouth portion 2. The inspirator head 35 has a gas nozzle housingcomprising a cylindrical portion 37 in the form of a casting the openends of which are pointing sideways. From the wall of the cylindricalportion 3'7 and at right angles to the horizontal axis thereof extendshorizontally a hollow neck portion 38 having an inner diameter Ddimensioned to fit over the mouth portion 1 of the injector member 36. Aset screw 39 provided in the neck portion 38 holds the inspirator headremovably in place upon and operatively connected with the injectormember 36. A gas supply connection 49 leads into the inspirator head 35which is formed with a gas supply passage 41. A gas nozzle or jet 42 isprovided within and rigidly connected with the cylindrical portion 37 ofthe gas nozzle housing to connect with the gas supply passage 41. Thisgas nozzle is horizontally coaxial with the injector member 36 andadjustably spaced from the mouth 12 thereof in a manner to inject intothe distributor tube a mixture of gas and air of desired proportions, asis indicated by arrows R.

In the operation of the burner, the position of the gas distributor tubeis suitably such that the gas passages face substantially downwardly soas to facilitate or encourage even gas distribution throughout and alongthe respective burner chambers.

With respect to zonewise adjustment of the flame intensity along theburner mouth, reference is made to Figures 2, 3, 4 showing examples ofblank-off adjustments of the blank-off tubes T. Figure2 illustratesanadjustment of flame distribution along the burner mouth, whereby outerend Zones d and f become zones of relatively greater flame intensity,whereas an intermediate zone e is of diminished flame intensity. Figure3 illustrates an adjustment whereone end zone g is of higher flameintensity,

whereas the balance of the length of the flame as represented by alonger zone h is of relatively diminished flame intensity. According tothe Figure 4 adjustment there is an intermediate zone k of higher flameintensity, whereas the end zones i and l are of relatively diminishedflame intensity.'

The position fixingmeans for the blank-01f members need not be limitedto the specific embodiment here shown, although suitable cutout area istobe provided in the wall of the distributor tube, through which theblank-off members can be reached for adjustment, together with means formaintaining them in adjusted position.

What is claimed is:

1. A gas burner of an elongate ribbon-flame type comprising an elongateburner housing having an elongate burner mouth extending substantiallyalong the effective length thereof, a longitudinal gas distributing tubewithin said housing, a gas inlet head connected with the burner housingto operatively communicate with said distributing tube for supplying gasthereto, and transverse partitioning means provided between said tubeand said housing to establish thereby within the housing a longitudinalsequence of gas supply chambers communicating with said burner mouth anddefining corresponding zones of flame control, said; gas distributingtube having gas passage area for each ofsaid chambers as well asblank-0E means adjustable for varying the'gas passage area individuallyfor each chamber and thus varying the rate of gas supply thereto fromsaid tube for effecting zonewise flame control; characterized therebythat mounting means are provided for fixedly supporting the inlet end ofthe burner housing as well as the gas inlet head thereof, that thepartitions means are in the form of at least one internal annular ribunitary'with said housing and presenting a bore to-have said gasdistributing tube removably extend therethrough in substantially gassealing relationship therewith, said gas inlet head comprising a membernormally rigidly and operatively connected with respect to said burnerhousing as well as with respect to said mounting means anddisconnectable with respect to said housing and to'said mounting meansto allow for longitudinal withdrawal. from the housing of the gasdistributing tube, that the adjustable blank-off means are disposedwithin said tube, and. that cutout area is provided in the tube'wall,with the addition of position-fixing means operable for securing theadjusted position of respective blank-off means when the tube has beenwithdrawn from the housing, said position-fixing means comprising alocking member extending outwardly from said blank-off means into saidcutout area and operable to engage the edge portion defining the cutoutarea, for securing an adjusted position of said blank-off means, saidlocking member thus engaged being substantially flush relative to thecircumference of the tube to provide for clearing the bores of thepartitioning ribs during the longitudinal movement therethrough of thetube when the same is withdrawn or inserted relative to the burnerhousing.

'2. The gas burner according to claim 1, in which said position fixingmeans comprise a screw having flat head provided with a conical seatingsurface and threaded into said blank-off means and adapted whentightened to have conically countersunk and position-fixing engagementwith the edge portion defining the associated cutout area of the tubewall, said edge portion being bevelled substantially corresponding tothe conicity of said head of the screw.

3. The gas burner according to claim 1, in which said cutout areacomprises an elongated auxiliary opening and the position fixing meanscomprise a screw having a flat head provided with a conical seatingsurface and threaded into said'blank-oif means and adapted whentightened to l conicity of said head of the screw.

4. The gas burner according to claim 1, in which the gas passage areacomprises elongated openings extending longitudinally of the tube, inwhichsaid cutout area comprises an elongated auxiliary opening extendingtransversely of the tube, and the position fixing means comprise a screwhaving a fiat head provided with a conical seating surface and thereadedinto said blank-off means and adapted when tightened to have countersunkand positionfixing engagement with the edge portion defining therespective transverse auxiliary opening, said edge portion beingbevelled substantially corresponding to the conicity of said head of thescrew.

5. The gas burner according to claim 1, in which said blank-off meanscomprise a length of blank-elf tubing substantially conforming to theinner curvature of the distributor tube and slidably movable therein andprovided with gas passage area substantially corresponding to theassociated gas passage area of the distributing tube, and in which theposition fixing means comprise a screw having a flat head provided witha conical seating surface and threaded into said blank-off tubing andadapted when tightened to have countersunk and position fixingengagement with the edge portion defining the associated cutout area,said edge portion being bevelled substantially corresponding to theconicity of said head of the screw.

6. The gas burner according to claim 1, in which said housing iscompartmented by a pair of said annular partitioning ribs to provide foran intermediate chamber with the gas passage area adjustable relative tothat of the adjoining end chambers of the flame.

7. Thegas burner according to claim 1, in which said gas inlet headcomprises a hollow gas inlet fitting disposed substantially coaxiallywith the burner axis and having communication with saidgas distributingtube, in which said fitting has. a lateral gas supply connectionextending substantially transversely of the said axis, said fittinghaving at the outer end thereof a removable closure member allowing forthe withdrawal through said fitting of said gas distributing tube whensaid closure member is removed.

8. The gas burner according :to claim 1, in which said gas inlet headcomprises a gas inspirator head having a gas nozzle housing, and meansare provided for disconnectibly connecting the nozzle housing relativeto said mounting means, relative to said housing and also relative tothe venturi-sha-ped constriction member mentioned below, with theaddition of a venturi-shaped constriction member surroundedinjector'fashion by said gas nozzle housing and connected in coaxialrelationship with the inlet end of said distributing tube, and meansfordisconnectibly connecting said constriction member relative to saidmounting means and relative to said burner housing, said venturi-shapedmember thus being removable from the burner housing and from saidmounting means as a unit together with said tube.

9. A gas burner according to claim 1, in which said gas inlet headcomprises a gas inspirator head having a gas nozzle housing, and meansare provided for disconnectibly connecting the nozzle housing relativeto said mounting means, relative to said housing, and also relative tothe venturi-shapcd constriction member mentioned below, with theaddition of a venturishapcd constriction member surroundedinjector-fashion by said gas nozzle housing and connected in coaxialrelationship with the inlet end of said distributing tube, and means fordisconnectibly connecting said constriction member relative to saidmounting means, and relative to said burner housing, said venturi-shapedmember thus being removable from the burner housing and from saidmounting means as a unit together with said tube, with the furtheraddition that the firstmentioned connecting means comprise a connectiondirectly between said venturlhapcd member and the gas nozzle housingsurrounding it.

it). The gas burner according to claim 1, in which said gas inlet headcomprises a gas inspirator head having a gas nozzle housing, and meansare provided for disconnectibly connecting the nozzle housing relativeto said mounting means, relative to said housing, and also relative tothe venturi-shaped constriction member mentioned below, with theaddition for a venturi-shaped constriction member surroundedinjector-fashion by said gas nozzle housing and connected in coaxialrelationship with the inlet end of said distributing tube, and means fordisconnectibly connecting said constriction member relative to saidmounting means, and relative to said burner housing, said venturi-shapedmember thus being rcmovable from the burner housing and from saidmounting means as a unit together with said tube, with the furtheraddition that the firstmentioned connecting means comprise a connectiondirectly between the inlet end of the burner housing and the inner sideof said mounting means, and that the lastmentioned connecting meanscomprise a connection directly between said constriction member and theouter side of said mounting means, as well as a connection directlybetween said constriction member and the nozzle housing surrounding it.

11. A gas burner of the longitudinal ribbon flame type in which alongitudinal burner housing has a longitudinal burner mouth, alongitudinal gas distributing tube within said housing, and a gasinspiralor head connected with the burner housing to operativelycommunicate with said distributing tube for supplying gas thereto;characterized thereby that mounting means are provided in the form of ashield plate having a threaded opening for fixedly supporting thereinthe inlet end of the burner housing, with the addition of aventuri-shaped constriction member surrounded injector-fashion by saidgas inspirator head seated upon and disconnectibly connected in coaxialrelationship with the outer free end of said constriction member, saidconstriction member having a threaded intermediate portion screwed intothe outer end of said threaded opening and thus outwardly removabletherefrom together with said distributing tube, the adjacent end of saidburner housing having a threaded end portion screwed into the inner endif said threaded opening.

References Cited in the file of this patent UNITED STATES PATENTS1,172,295 La Moy Feb. 22, 1916 2,565,831 White Aug. 28, 1951 FOREIGNPATENTS 567,538 Great Britain Feb. 19, 1945

